1. Field of the Invention.
This invention relates to an anti-siphon faucet that is capable of complete water drainage from that portion of the faucet that projects into the atmosphere from a building so as to prevent water from freezing therein in below freezing weather.
2. Description of the Prior Art.
There has been some prior work in the development of anti-siphon frost free faucets. However, in the developments of such faucets a major problem has developed. Generally, the faucet construction has not allowed complete emptying of the faucet at the water discharge end.
There have been facets that possess a vacuum breaker (anti-siphon) feature and back flow preventer means. Such a faucet is shown in U.S. Pat. No. 3,414,001 to Woodford. However, this patent does not have separate air vent and drainage combination means to allow drainage of water in the faucet when the water source is turned off.
U.S. Pat. No. 3,494,373 to Horak is for a frost free faucet but it calls for removal of a part of the faucet at the building wall to prevent vandalism. Further, should the removable section be left in the faucet mounted in the wall when the water is turned off water in the removable section would not be completely drained.
Finally, applicants are knowledgeable of U.S. Pat. No. 3,929,150 which illustrate a back flow preventer and anti-siphon means, however, the valving is complicated and requires an internal tube within an outer tube to provide two passages so that one may communicate with a bleed off valve. However, again there is no full assurance that without water pressure full drainage of the internal tube can be accomplished.